52 AUSTRALIAN SKY & TELESCOPE May | June 2018
TARGETSM58: JEREMY PEREZ; M87: DALE HOLTGalaxies in Virgo
Object Type Mag(v) Surface
BrightnessSize/Sep RA Dec.M87 Giant elliptical 8.6 13.0 8.3′ × 6.6′ 12 h 30.8m +12 ° 2 3′
NGC 4478 Elliptical 11.5 12.6 1.9′ × 1.6′ 12 h 30.3m +12 ° 2 0′
NGC 4 476 Lenticular 12.2 12.8 1.7′ × 1.1′ 12 h 30.0m +12 ° 2 1′
M89 Elliptical 9.8 12.5 5.1′ × 4.7′ 12 h 35.7m +12 ° 3 3′
NGC 4550 Barred lenticular 11.7 12.7 2.9′ × 0.8′ 12 h 35.5m +12 ° 13′
NGC 4551 Elliptical 12.0 13.0 1.8′ × 1.4′ 12 h 35.6m +12 ° 16′
M58 Barred spiral 9.7 13.1 5.9′ × 4.7′ 12 h 37.7m +11° 4 9′
NGC 4564 Elliptical 11.1 12.9 3.5′ × 1.5′ 12 h 36.5m +11° 2 6′
NGC 4567 Spiral 11.3 13.1 3.0′ × 1.4′ 12 h 36.5m +11° 15′
NGC 4568 Spiral 10.8 13.1 4.3′ × 1.0′ 12 h 36.6m +11° 14′
Angular sizes and separations are from recent catalogues. Visually, an object’s size is often smaller than the cataloged value and
varies according to the aperture and magnification of the viewing instrument. Right ascension and declination are for equinox 2000.0.1 ′ long. While gazing at NGC 4478, I
noticed NGC 4476 with averted vision.
It’s a bit smaller but more elongated
than NGC 4478, leaning north-
northeast, and too faint to disclose
any details. NGC 4478 and NGC
4476 delineate the top of an 8.2′-tall
trapezoid that they form with two
11th-magnitude stars to their south-
southwest.
My 25-cm reflector at 187× shows
M87’s 5′-long face cocked north-
northwest. The interior is bright to a
diameter of approximately 2½′, and
it grows much brighter toward the
centre. NGC 4478 is easy to spot,
covering about 1¼′. Its fairly bright core
intensifies inward to a tiny nucleus.
NGC 4476 shows well now, brightening
slightly toward an elusive nucleus.
M87 is famous for its narrow plasma
jet, which is powered by the accretion
disk around the galaxy’s central,
supermassive black hole. It’s not
surprising that amateur astronomers
would love to see this beast, but it’s
quite astonishing that many have
succeeded. This isn’t an undertaking
for the faint of heart. Those who have
succeeded are accomplished observers
working under excellent skies and using
magnifications of about 400×. Most
used 50-cm and larger telescopes, but
some triumphed with scopes as small
as 31.8 cm in aperture. From the heart
of the galaxy, the jet strikes out west-
northwest for about 21′′, but the part
that is most likely to be visible is the
stretch from 12′′ to 18′′. If you decide
to attempt this feat, be careful not to
mistake the extremely faint galaxy pair
(UGC 7652) 2′ southwest of M87 for
the jet.
Placing M87 in the western side of
the 130-mm scope’s 23× field of view
brings Messier 89 into view, looking
smaller than M87 and round with a
bright centre. At 63× M89 displays
a moderately faint halo, a brighter
interior and a small, intense core — all
round. Boosting the magnification to
117 ×, the scope teases out a starlike
nucleus. The galaxy’s halo fades into
the background sky at a diameter ofabout 2′. My 25-cm scope at 166×
reveals a 13th-magnitude star watching
over the halo’s east-northeastern edge.
On deep images, M89 sports what
appears to be a jet that extends a
whopping 10′ from the galaxy’s centre.
However, this ‘jet’ is composed of stars
and may be the product of an encounter
with a smaller galaxy.
Only 20′ south of M89, we find
the galaxy pair NGC 4550 and NGC
4551. In a 1992 Astrophysical Journal
paper, Vera Rubin and colleagues
published an amazing find. Rubin
later commented, “I discovered from
observations of NGC 4550 that in
the single disk of this galaxy, half the
stars orbit clockwise, and half the
stars orbit counterclockwise, both
systems intermingled. This observation
required that many astronomers modify
the manner in which they measured
velocities, for computer programs wereX Under very high
power, the irregular
structure of the
barred spiral M58
may be revealed.
The typical view
through an 20-cm
relector is shown
here. The galaxy is
tipped slightly toward
the east-northeast and appears
brighter at its core.SWith the right equipment, you may be able
to detect the high-energy jet of particles
emanating from M87’s supermassive black
hole. This sketch represents the plasma
stream as viewed with a 50-cm Newtonian
relector and deep sky video camera.not then equipped to handle such
complexity. A nice discovery to make
at age 63!” Few galaxies are known to
have such a large dichotomy, a feature
that might be due to the merger of two
galaxies with misaligned spins.
With a wide-angle eyepiece that
gives 117× through the 130-mm scope,
NGC 4550 and NGC 4551 share the
field of view with M89. The very faint,
1½′-long, north-south spindle of NGC
4550 is enclosed in a trapezoidal box
of four stars, magnitudes 12 and 13.
The box is 5½′ tall, with the galaxy just
beneath (west of) its lid. Dimmer andNM58NM87